Golden opportunity – Helping a major gold plant identify US$54 million in ‘missing’ production

When comparing calculated and actual production values, the owners of a gold plant in Asia found their reconciliation was out by around 900 kilograms over three months—to the value of US$54 million. Calculated gold throughput simply did not match that of the gold in the poured doré bars. The team contacted Metallurgical Systems to conduct an audit and provide consulting services to identify areas for improvement.


The plant had challenges in three key areas. The first was instrumentation – some of which was unverified or had material build-up. There was also no flowmeter or density meter instrumentation at critical points. Another issue was sampling, which was overly manual, and infrequent. Data management was also a challenge. Important data was stored in spreadsheets, there was no robust change management, and the timing of reconciliations was somewhat ad-hoc.


The plant provided Metallurgical Systems with instrumentation and lab data for a six-month period. Among other things, it was confirmed that the plant’s mill feed weightometers were over-reading by 20%, and the flash flotation flowmeter was also over-reading by 30%. The plant was able to make improvements and upgrades to the weightometer frame to address this.


Armed with the framework of recommendations from Metallurgical Systems, the client has been able to make progress and identify reconciliation issues that were significantly impacting the plant’s profitability. Most importantly, the plant has been able to close the gap between its ‘calculated’ and ‘actual’ measurements.